Fluid system



Patented Mar. 4, 1941 PATENT OFFICE FLUID SYSTEM Lyman F. Whitney, Cambridge, Mass, assignor, by mesne assignments, to Stator Corporation, a corporation of Rhode Island Application October 14, 1937, Serial No. 168,957

7 Claims.

This invention relates to heat exchange sys tems, and more particularly to refrigerating systems of the type which receive their energy from a source of heat and have relatively low pres- 5 sures, so that pressure differences may be balanced by liquid columns.

The present invention provides safety means which becomes-automatically operable to absorb heat when an excessive amount of heat is supm plied to the boiler of the refrigerating system or the like. This arrangement, for example, may be employed in a refrigerating system of the general character disclosed in United States Patent No. 1,761,551 to Eastman A. Weaver, wherein l5 mercury is vaporized to provide a stream of propelant vapor which pumps refrigerant vapor from a cooler to a condenser, the boiler pressure being balanced by a column of the condensed propellant, e. g., mercury. Under some practical 20 .operating conditions the heater of such a systern may be improperly adjusted so that it would tend to cause abnormal operation of the system and possible denuding of the boiler. When the boiler of such a system receives an abnormally 25 high quantity of heat, the pressure balancing mercury column tends to increase in height, and eventually the mercury might overflow from the top of this column and the boiler would be denuded at the high temperature then prevailing.

30 In accordance with this invention, a spill-over arrangement may'be provided to receive liquid from the top of the pressure-balancing column when the column reaches a predetermined height, and an auxiliary or safety boiler receives 35 the propellant which has thus spilled over. This auxiliary boiler is in heat transfer relation to the main boiler, so that when the former contains a body of liquid, it tends to reduce the temperature of the mainboiler. A heat dissipator is provided to condense vapor supplied by the auxiliary boiler and to return the condensed vapor to the main propellant circuit.

A further aspect of the invention relates to the provision of trap means containing a liquid body 5 to balance pressure differences, and arranged so that the liquid body may be automatically replenished under all operating conditions.

In the accompanying drawing, the figure is a diagrammatic view of a refrigerating system so constructed in accordance with the present invention.

A system'of the character to which the present invention is directed may be provided with a 'heater 1, such as a gas burner, which supplies 55 energy to the system. This burner, for example,

oration of the liquid in the cooler I. The mixed vapors pass into the funnel 8, where the refrigerant vapor is compressed and propellant is condensed. The funnel 8 is provided with cooling means, such as fins ID, to aid the condensation of the propellant. The compressed refrigerant passes from the funnel through the duct 12 to the refrigerant condenser it, while condensed propellant is received from the funnel by a drain I5. This drain comprises one leg 'of a trap 16, the opposite leg of which communicates with an entraining chamber 20 of a purger 2| of the type more fully disclosed in my copending application Serial No. 167,402, filed October 5, 1937.

The refrigerant condenser [4 may be of any desired form and may be provided with any suitable cooling means, such as the fins 22. The condenser may also be provided with a gas-collecting drum 23, this drum preferably being arranged below the portion of the condenser which is provided with the cooling means. This drum receives the condensed refrigerant and the noncondensible gases which appear in the system.

A .purger supply tube 25 receives the gases from the drum 23 and supplies them to the entraining chamber 20 of the purger. The latter is provided with a capillary drop tube 23 in which successive globules of the propellant liquid entrain bodies of the non-condensable gas, compressing the same as they move downwardly in the tube. The gas and propellant flowing out of the lower end of the tube is received by a body 24 of liquid propellant in a vat 25, the upper surface of this propellant body being exposed to the atmosphere so that the gas or air may bubble upwardly through the liquid body and be exhausted to the atmosphere.

A deflector 26 of the type disclosed in the copending application of Raymond W. Tibbets, Serial No. 168,958, filed October 14, 1937, is arranged at the lower end of the drop tube 23 so that the gases .emitted from the tube cannot rise into the return duct 30, but so that propellant may rise in the same and may spill over into the heavy propellant.

duct 35. If desired, a very small vent (not shown) may be arranged between chamber 20 and duct 30, as disclosed in my application Serial No. 167,402, to permit pressure equalization in these parts of the system. The duct 35 is connected to a trap 36, the opposite leg of which communicates with a boiler return pipe 31. The upperend of the pipe 31 communicates with the lower part of mixing chamber 5, so that propellant particles which condense in this part of the system may drain back to the lower part of pipe 31. Undernormal operating conditions the pipe 31 contains a column of propellant which balances the boiler pressure.

The condensed refrigerant which is received by the drum23passes into a drain which is connected to a trap 4| containing a body of the As the refrigerant piles up in the drain it provides a liquid head suflicient to cause some of the refrigerantto bubble through the trap'4l and thence pass through the duct 44 back to the cooler 1, it being evident that the propellant in trap 4| balances the difference in pressure between the cooler and the condenser.

In accordance with this invention, a secondary or safety boiler may be provided in heattransfer relation to the heater I and boiler 2. The boiler 50, for example, may comprise a metal dome welded to the upper part of the boiler 2, A duct 53 extends upwardly from the secondary boiler 50 and has a spill-over connection through duct 54 with the return pipe 31, the duct 54 preferably inclining downwardly toward the return pipe. The duct 53 is continued upwardly beyond its connection with the pipe 54, and its upper end communicates with a heat dissipator 55, which may be in the form of a duct section provided with a plurality of cooling fins. This duct section inclines downwardly from its connection with the duct 53 and communicates with a duct 51 connected to the lower part of trap 36.

A duct communicates with the upper end of duct 51 and is provided with a trap 61 connected.

to the bottom of the cooler, so that condensed propellant particles passing into the cooler may be received by the trap 6| and may spill over from the latter into the duct 60, thus being received by the duct 51 and'the trap 36.

The arrangement of duct 51 so that it supplies mercury to the lower part of trap 33 is particularly advantageous under certain operating conditions, since it permits the pressure-balancing body of mercury constantly to be replenished and maintained in the trap, The pipe 60 inclines downwardly from its connection to the upper part of duct 51 and has a connection with the upper part of the return pipe 31, this connection per- I mitting substantial equalization of I pressures above the legs of trap GI.

The safety boiler 50 normally is empty and the pressure-balancing column in pipe 31 may stand, for example, at substantially the level shown in the accompanying drawing; However, should the burner I be improperly adjusted so that too much gas is being supplied to the same, the boiler pressure rises and the height of the liquid column in pipe 31 ris'es correspondingly until it reaches the spill-over connection 54, whereupon the mercury from the top 01' the column spills over through the pipes 54 and 53 to the secondary boiler 50.

Since under such conditions the boiler 50; is at a relatively high temperature the mercury which is received thereby is vaporized, thus absorbing some of the heat from the heater I and tending to reduce the temperature of the boiler 2. The resulting mercury vapor passes upwardly through the duct 53 to the dissipator! 55 where it is condensed. The resulting condensate drains into the duct 51, being received by the trap 36 and directed by the latter to the return duct 31. Some of the vapor from the secondary boiler 50 may be received by the spill-over pipe 54,

suflicient mercury i kept in the boiler to prevent denuding thereof and consequent liability of injury to the system.

It is evident that the present invention affords a safety arrangement automatically operable to absorb heat from a boiler when an excessively large amount of heat is supplied to the same.

and such an arrangement is particularly useful in a system such as a low pressure refrigerating system, wherein the boiler pressure is balanced by a liquid column. I

It should be understood that the present disclosure is forthe purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. Heat exchange system comprising a main boiler, a heater to supply heat to said boiler, a secondary boiler which is normally empty, and means responsive to an increase in the pressure of the main boiler beyond a predetermined-point thereupon to supply liquid to the secondary boiler, said secondary boiler then being effective in absorbing some of the heat supplied by the heater so that the pressure in the main boiler may automatically be prevented from rising further.

2. Heat exchange system comprising a main boiler, a heater to supply heat to said boiler, a

secondary boiler which is normally empty, and.

means responsive to an increase in the pressure of the main boiler beyond a predetermined point thereupon to supply liquid to the secondary boiler, said secondary boiler then being eife'ctive in absorbing some of the heat supplied by the heater so that the pressure in the main boiler may automatically be prevented from rising further, a heat dissipator receiving vapor from the 1 secondary boiler, condensing said vapor and directing the resulting condensate to the main boiler, whereby the secondary boiler may be denuded when the pressure in the main boiler falls below a predetermined point.

3. Heat exchange system comprising a main boiler, a heater for supplying heat to said boiler, a normally inoperative heat dissipator, and means operable in response to an undue rise in the boiler pressure to cause the dissipator to become operative in receiving some of the heat supplied by the heater and dissipating the same, whereby the boiler is protected against overheating.

4. Heat exchange system comprising a main boiler, a duct connected to the boiler and containing a column of liquid balancing the boiler pressure, a secondary boiler which is normally the heater, means receiving liquid from the top of the column when the column reaches a predetermined height in response to a rise in the pressure of the main boiler, said means sulllplying the liquid to the secondary boiler so that the latter absorbs some 01' the heat supplied by the heater,

.2 heat dissipator receiving vapor from the secondary boiler, condensing said vapor and returning the resulting condensate to the liquid column in said duct.

5. Heat exchange system comprising a fluid circuit including a main boiler and a condenser, a secondary boiler in heat-transfer relation to the main boiler, said fluid circuit also including a return duct connected to the main boiler and containing a column of liquid balancing the main boiler pressure, said secondary boiler receiving liquid which spills over from the top oi said columnaiter the column reaches a predetermined height in response to a rise in the pressure of the main'boiler, a heat dlssipator which receives and condenses vapor from the secondary boiler, said dissipator returning the resulting condensate to the liquid column in said duct.

6. Heat exchange system comprising a fluid circuit including a main boiler, a condenser, a trap receiving condensate from the condenser, and a returnduct connected to the main boiler and containing a column of liquid balancing the main boiler pressure, said duct receiving condensate 'from the trap and returning the same to the boiler, a secondary boiler in heat transfer relation to the main boiler, said second boiler nor- .mall being empty, said secondary boiler receiving liquid which spills over from the top of said column alter the column reaches a predetermined height in response to a rise in the pressure oi.

the main boiler, a heat dissipator which receives and condenses vapor from the secondary boiler, a duct receiving the resulting condensate from the dissipator and directing thesame to the lower part of said trap whereby said last-named condensate may also be returned to the main boiler.

7. Refrigerating apparatus of the class described comprising a propellant circuit and a re- Irigerant circuit having a part in common where propellant vapor pumps and compresses refrigerant vapor and where the propellant vapor is condensed, said propellant circuit also including a boiler, a vapor pipe connecting the boiler to said common part, and a return pipe connecting said common part and the boiler, said refrigerant circult also including a cooler and a refrigerant condenser, a receptacle in heat transfer relation to the boiler, a duct extending upwardly from said receptacle, a heat dissipator connected to the upper end or said duct and to the propellant return pipe, said receptacle, duct, dissipator and return pipe being arranged so that under normal operating conditions a column of liquid propellant in the pipe balances the boiler pressure, but so that, when the boiler pressure rises unduly, propellant spills over into the upwardly extending duct and receptacle, being vaporized in the latter and condensed in the dissipator, thecondensed propellant draining from the disslmtor back said return pip whereby when an large quantity of heat is supplied to the boiler the excess heat will be employed in vaporizing propellant in said receptacle.

LYMAN F. WHITNEY. 

